Technician a Says That Servo-Hydraulic Injector Actuators Use a Small

Technician A says that servo-hydraulic injector actuators use a small amount of control valve movement to control larger, more powerful, and faster-acting hydraulic forces. Technician B says that control valves that use piezoelectric technology are the only actuators capable of servo action. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B